Electric switch



(No Model) l y l J. F. MGLAGHLIN.

B-LEGTMG SWITCH. 5 A N0 432,207 Patentd July-15, 1890.

UNITED ASTATES PATENT OFFICE.

JAMES F. MCLAUGIILIN,l OF PHILADELPHIA, PENNSYLVANIA.

ELECTRIC-SWITCH.

SPECIFICATION forming part of Letters Patent No. 432,207, dated July 15,1890. Application ned April 1'7, 1890. serial No. 348.330: (No model.)

T0 all whom, it may concern:

Beit known that 1, JAMES F. MCLAUGHLIN, a citizen of the United States,and a resident of Philadelphia, in the county of Philadelphia and Stateof Pennsylvania, have invented certain new and useful Improvements in`Electrical Switches, of vwhich the following is a specification. Y

This invention has reference to improvements in electric switches; andits main object is to switch a measuring-instrument into or out of thecircuit Withoutbreaking orotherwise materially alfecting thelatter.

It consists, essentially, of a switch-arm included in the main circuitand two contact- /plates in the path of said arm, on e being in- .cludednormally in the .main circuit and the other in a circuit including themeasuringinstrument, the arrangement being such that inl 011e positionof the switch the current from the generator flows directly to thetranslating device and in the other position of the switch to which itis turned without at any time breaking the circuit themeasuring-instrument is included in the circuit with the' translatingdevice.

There are special advantages, due to some of the features entering intothe construction of the improved switch, which are applicable to otherswitches, and these Vadvantages will appear from thc following detaileddescription, in which reference is had to the accompanying drawings,forming part of this speci- Ication; but to the exact constructionillustrated therein I am in no manner confined, since, as willbeevident, such construction may be variously modified without departingfrom the spirit of my invention.

In the drawings, Figure 1. is a plan View of the switch with the sourceof electricity and translating and measuring devices and thecircuit-connections shown diagrannnatically. Fig. 2 is a similar view ofthe switch with the switch-arm in a central position bridging the twocontact-plates. tion on the line fr. of Fig. 2. Fig. Liis a sectiontaken on the curved line y1] of Fig. 2. Fig. 5 is a similarsection of amodified form of the device shown in Fig. 4, and Fig. G is a plan of adetail of the apparatus shown in Fig. 4.

Referring to the drawings, there is shown Fig. 3 is a vertical sec abase 1, of any suitable insulating material, in which is seated acasting 2, consisting of two posts 3 4,joined at their lower ends, and55 spaced a distance apart by an integral portion of the casting. lThetwo posts 3 4 extend through the base 1 and above the face of the same,while the portion of the casting joining the two posts is seated in arecess formed 6o on the under side of the base, so that the bottom ofthe casting is flush with the latter, and through this said portion ofthe casting 'n extend screws 5, which serve to secure it to the base 1.

The post 3 is reduced in size at its upper end, as shown at G, to formaspindle or pivot for a switch-arm', which is held at a distance abovethe base 1 by the shoulder of the spin.- die, as shown, and it isprevented from being 7o lifted from the post by a screw 8, entering anut formed in the said post, and between the head of the screw and theupper face of the switch-arm there isinterposed aspring-washer 9, whichserves to maintain at all times good electrical contact' between theswitch-arm and its supporting-post. At the out-er end the switch-arm isprovided with a manipr lating-handle 10, of insulating materiahan at theinner end it is slightly expanded, as 8o shown at 11. In the path of theexpanded end of the switch-arm there are two curved contact plates orblocks 12 13, with their adjacent ends a-t such distance apart that.tl1esaid expanded end 11 of the switch-arm on 85 passing from onecontact-plate to the other will bridge the space between them, and

thereby establish good contact with one plate before leaving the other.

The base 1 is recessed, as shown at 14, to 9o receive thecontact-plates, which are held thereto by screws 15, passing looselythrough the base and projecting upward and entering nuts formed in thesaid contact-plates. The holes in the base 1 for the passage of ther 95screws 15 are eountersunk, as shown at 16, to receive thescrew-heads'and permit the screws to have a limited longitudinalmovement, which is participated in by the contactplates 12 and 18.Within each recess 14 in the loc form most clearly shown in Figs. 2 and4 there is a curved spring-plate 17, provided with a central perforation1S for the passage of the screw 15, and end slots 19 for the passage ofguide-pins 20, depending from the contact-block and entering holcs 21 inthe base 1. The spring-plates 17, it will be observed, are curved in oneplane to conform to the shape of the contact-plates and recesses 14, andare also curved in another plane, so that the ends support the saidcontact-plates at a distance above the bottoms of the recesses 14limited by the screws 15. At their highest point the contact-plates havetheir upper or contact faces slightly above the lower or contact face ofthe switch-lever, and when the latter is moved over the saidcontact-plates the supporting spring-plates 17 yield sufficiently topermit such operation,

thus insuring at all times good electrical contact between theswitch-arm and plates and providing a means which compensates for wearbetween the contact-surfaces. The two adjacent ends of thecontact-plates may be beveled at their upper edges or corners, as shownat 22, so that the switch-arm may ride easily onto the surfaces of thesaid contactplates.

-A slightly-modified form of mounting for the contactfplates is shown inFig.5, in which the spring-plate 17 is replaced by helical springs 23,surrounding theguide-pins 2O and interposed between each of the saidcontactplates and the vbottom ot the respective recess 14. y

The switch constructed as described is included in a main circuit, alsoincluding a battery 24 or other suitable source of electricity and atranslating device 25, which in the present instance is diagrammaticallyrepresented as an electric motor. The terminal of a conductor 96, comingfrom the battery 24 and forming a part of the main circuit, is -mnected.to the contact-plate 12 by means of 'binding-screw 527, or oth crwise,and another 'iductor 2S, also forming part of the main circuit andconnected to the motor, is secured to the post 4 by means of abinding-screw 29. The. contact-plate 12 is connected toameasuringinstrument P30 by a conductor 31, secured to the saidcontact-plate by the screw 27, and thc contact-plate 13 is alsoconnected to the measuring-instrument 30 by a conductor 32. \Vhen theswitch-arm is on the contact-plate 12, the current will pass by theconductor 26 from one pole of the battery through the contact-plate 12,the switch-arm, the casting 2, and the conductor 28 to the motor25,-fron1 whence it will return to the other pole of the battery.

IVhen it is desirable to introduce the measuring-instrumentinto thecircuit, the switch is moved onto the other contact-plate 13, when thecurrent will pass from the battery by the conductors 26 and 3l to themeasuring-instrument 30, thence by the conductor 32, contactductor 28 tothe motor, from whence it returns to the battery.

It will be observed that the measuring-instrument may be switched intoor out of the circuit without at any time breaking the circuit from thebattery to the motor, for, as has been before explained, the switch-armmakes contact with one contact-plate before it leaves the other.

I claim and desire to secure by Letters Patent- 1. ln an electricswitch, the combination, with two contact-plates and a switch-armadapted for making contact with either or both of the contact-plates, ofa. charged electric circuit with a translating device therein,terminating in one of the contact-plates and in the switch-arm,respectively, and an electric measuring device, the terminals of whichare connected with the two contact-plates, respectively, substantiallyas described.

2. In an electric switch, the combination, with a suitable base and apivoted switch-arm, of curved contactfplates in the path of said arm,and springs interposed between the base and contact-plates, said springsbeing curved in one plane to conform to the shape of the contact-platesand bent up at the ends to support the ends of said plates, and beingitself supported in the middle, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JAMES F. MCLAUGHLIN.

Witnesses:

HERBERT P. KER, EDWIN F. GLENN.

plate 13, the switch-arm, cast-ing 2, and con- Having now fullydescribed my invention,

